[Just09]

This is the solution, navigate to C:\ProgramData\BlueStacks\UserData\InputMapper and open the cfg file com.supercell.clashofclans with notepad. Add the following lines ad save. Restart BS. For me worked perfectly.

# ALWAYS_SEND_UNMAPPED_KEY
# Clash Of Clans
[Origin]
Author = Harsh
Rating = 4.0
[Keys]
Down = Swipe Up (20,50); Swipe Down (60,20)
Up = Swipe Down (20,50); Swipe Up (60,20)
[Guidance]
Down = SDown
Up = SUp
[Gamepad]
A = Down
B = Up
[OpenSensor]
Mode = Tap
A = Up SUp
B = Down SDown
[Strings]
SDown = Zoom Out
SUp = Zoom In

Yea I find this early, but thanks.